Page 55 - Science Course 1 (Book 2)
P. 55
Mo8-L3a: What are the Uses of Thermal Energy?
Most cars, buses, boats, trucks, and lawn mowers
use a type of heat engine called an internal
combustion engine.
Internal Combustion Engine
The intake valve opens as A spark plug ignites the fuel-air
the piston moves downward, mixture. As the mixture burns,
drawing a mixture of gasoline hot gases expand, pushing the
and air into the cylinder piston down.
1. Intake 3. Fuel Power
The intake valve closes as
the piston moves upward, As the piston moves up the
compressing the fuel-air exhaust valve opens, and the
mixture. hot gases are pushed out of
the cylinders.
2. Compression 4. Fuel Exhaust
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